1. Field of the Invention
The present invention relates to a recliner mounted in a seat of a vehicle for controlling an angle of inclination of the back of the seat, and more particularly to a round recliner for a vehicle that is capable of minimizing occurrence of clearances in the recliner and preventing any irregular engagement of the recliner.
2. Description of the Related Art
As well known to those skilled in the art, one or more seats are provided in a vehicle, on which a driver or a passenger sits comfortably. In the seat are mounted a pair of seat fixing bases actuated by means of a lever for moving a seat back and forth, and a recliner mounted to the rear end of one of the seat fixing bases for rotating the back of the seat back and forth. The recliner is used for the driver or the passenger to adjust a rotational position of the back of the seat based on his/her body form.
The aforesaid recliner is usually mounted to one side of the seat fixing base to which an actuating lever is attached. When the vehicle collides with another vehicle or any structure, the back of the seat leans forward. At this time, the back of the seat attached to the seat fixing base where the recliner is not provided leans forward, whereas the back of the seat attached to the seat fixing base where the recliner is provided does not lean forward. As a result, a rotational force is generated about the recliner, and thus a repulsive force and the rotational force are applied to the back of the seat when the driver or the passenger is pushed forwardly.
A recliner as shown in FIG. 8 has been proposed in order to solve the aforesaid problems. As shown in FIG. 8, lower fixing members 2 are attached to the rear ends of seat fixing bases 1, respectively. To the lower fixing members 2 are pivotably attached upper fixing members 4 for controlling a rotating movement of the back of the seat. The recliner comprises a first recliner part having a lower gear 12 rotated by means of a rotational movement of a cam 13 effected by an actuating lever 10 for controlling a rotating movement of the back of the seat, and a second recliner part connected to the first recliner part via a shaft 14. The second recliner part has a link 15, by which the second recliner part can be cooperated with the first recliner part. At one of the seat fixing bases 1 is provided a nut hole 16, which is close to the lower fixing member 2. A safety belt 17 is fixed to the seat fixing base 1 by means of the nut hole 16.
As described above, the recliner is very complicated in its structure, with the result that the assembly of the recliner is difficult and the cost of manufacturing the recliner is increased. Furthermore, the nut hole provided for fixing the safety belt is formed at the front part of the seat fixing base due to the structure of the lower fixing member. Consequently, the safety belt does not function effectively when the vehicle collides with another vehicle or any structure.
Therefore, a recliner as shown in FIGS. 9 and 10 has been proposed in order to solve the aforesaid problems. As shown in FIGS. 9 and 10, the recliner comprises: a lock gear guiding groove 32 formed inside an upper actuating member 30 by means of blanking, in which a lock gear 50 is operatively arranged; an inner gear part 34 formed on the lower inner edge of the lock gear guiding groove 32 by means of the aforesaid blanking, the lock gear 50 being engaged with the inner gear part 34; a lock gear actuating groove 42 formed inside a lower supporting member 40 by means of the aforesaid blanking; an inner gear part 45 formed on the lower inner edge of the lock gear actuating groove 42 by means of the aforesaid blanking; a reinforcing portion 44 protruded from the lower supporting member 40, the reinforcing portions 44 being inserted into the lock gear guiding groove 32 of the upper actuating member 30, the lock gear 50 being actuated vertically by means of an actuating cam 60 in the lock gear actuating groove 42 of the lower supporting member 40; and a cam hole 54 formed in the lock gear 50, the cam hole 54 having a top end surface 56 and a bottom end surface 58, the top end surface 56 being in contact with a top end 62 of the actuating cam 60 and the bottom end surface 58 being in contact with a bottom end 64 of the actuating cam 60, the actuating cam 60 actuating vertically in the cam hole 54 of the lock gear 50.
The upper actuating member 30 and the lower supporting member 40 are securely fixed to each other by means of the lock gear 50, and the lock gear is actuated in the lock gear guiding groove 32 of the upper actuating member 30 and the lock gear actuating groove 42 of the lower supporting member 40. Consequently, twisting from side to side is reduced as compared to other conventional recliners even when any impact is applied to the recliner as the vehicle collides with another vehicle from the front or from behind, and thus any breakage of the lock gear 50 is prevented. Since the lock gear 50 and the actuating cam 60 are operated only by means of a shaft 70 in the lower supporting member 40, however, there is a clearance between the lock gear 50 and the actuating cam 60, which causes noise and vibration.
Furthermore, an outer gear part 52 is engaged with the inner gear part 45 of the lower supporting member 40 as well as the inner gear part 34 of the upper actuating member 30. Consequently, the assembly operation of the recliner is very difficult, and the engagement of the gear parts may be irregular, which also causes noise and vibration.
Moreover, when the recliner is loaded in front thereof or in the rear thereof, not only twisting of the recliner from side to side occurs but also shaking of the recliner occurs, whereby the load is not evenly applied to the outer gear part 52 of the lock gear 50. Consequently, a degree of strength of the recliner may be decreased, and the recliner may be easily damaged even by a light impact.